SUMMARY ? OVERALL CENTER The Oregon State University Superfund Research Program (SRP), in partnership with Pacific Northwest National Laboratories and other stakeholders and collaborators, seeks to develop new technologies to identify the polycyclic aromatic hydrocarbon (PAHs) mixtures found at many of the nation's Superfund sites before and after remediation. We will identify novel hazard and toxicity mechanisms for PAHs and real-world PAH mixtures. The SRP will support three biomedical research projects and two environmental science and engineering projects. We aligned these research projects with the four SRP mandates to address pressing challenges at Superfund sites. The Administrative, Community Engagement, Chemical Mixtures, Research Experience and Training, and Data Management and Analysis cores support the research projects. This proposal builds on our successes during the previous grant period. Over the next five years, we will pursue innovative, high-impact research goals. For example, we propose to (1) develop the first generalizable technology to measure the movement of PAHs to and from Superfund sites, (2) measure external exposures to PAHs for individuals near Superfund sites and determine how their exposures vary as a function of location, (3) predict the secondary transformation products of PAHs that will form during biotic and abiotic remediation at Superfund sites, (4) predict the toxicity of complex PAH mixtures using zebrafish, (5) link PAH exposure to health outcomes with the aid of a powerful human in vitro respiratory model, and (6) elucidate metabolic and physicochemical control of PAH susceptibility in toxicity systems. The cores will (1) direct the activities of the SRP and disseminate our findings to stakeholders (Administrative), (2) work with communities impacted by PAH exposure to address concerns and reduce risk (Community Engagement); (3) provide intensive multi-disciplinary training for the next generation of Environmental Health Scientists (RETCC), (4) provide data management and analysis support (DMAC), and (5) apply state-of- the-art chemistry instrumentation and approaches to measure PAHs and PAH mixtures found in environmental and biological matrices. By accomplishing these goals, we will advance the frontiers of science and also improve the quality of life for impacted communities.